Looper mechanism for overseaming sewing-machines



A. H. DE VOE.

LOOPER MECHANISMIOR OVERSEAMING SEWING MACHINES.

APPLICATIGN FILED MAR. II. ISIS.

1,334,651.' Patented Mar.23,1920.

2 SHEETS-SHEET r..

-A. H. mi voE. LOOPER MECHANISM FOR OVERSEAMING SEWING MACHINES.

APPLICATION FILED MAR. 11, 1918.

1,334,651. Patntd Mar. 23,1920.

2 SHEETS-SHEET 2.

WITNESS /NVENTH f1 TTRNE Y UNITED sTATEs PATENT oEEIcE.

.ALBERT H. DE VOE, OF WESTFIELD, NEW JERSEY', ASSIGNOR TO THE SINGER MANU- FACTURING COMPANY, A CORPORATION OF NEW JERSEY.

LOOPER MECHANISM FOR OVERSEAMING SEWING-MACHINES.

Specification of Letters Patent.

Patented Mar. 23, 1920.

Application filed March 11, 1918. Serial No. 221,594.

To all whom t may concern:

Be it known that I, ALBERT H. DE Von,

a citizen of the United States, residing at Westfield, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Loo er Mechanism for Overseaming Sewingachines, of which the following is a specification, reference being had therein to the accompanying drawings.

' This invention relates to an improvement in overseaming sewing machines, designed more particularly for covering the raw edges of materials as they are united, and disclosed for instance in U. S. patent to P. Diehl, No. 733,170, dated July 7, 1903.

The invention has for its primary object to improve the looper actuating mechanism of a sewing machine of this class by the provision of a construction of greater durability under conditions of operation of said looper at higher speeds than heretofore practicable.

According to the present construction, the looper is carried by an inclined rock-shaft, supported by a rocking arm having a fixed fulcrum, This rock-shaft is provided with a depending crank-arm connected by a link with a second rocking arm mounted upon a fixed fulcrum parallel with and in advance of that of the looper carrying arm. The rocking arms have independent link connections with an actuating rocker upon a transverse rock-shaft actuated from the driving shaft of the machine.

In the accompanying drawings, Figure 1 is a perspective view of the machine with certain parts removed to better illustrate the actuating connections for the looper. Fig. 2 is an end elevation of the same. Figs. 3 and l are front side elevations illustrating the looper-actuating mechanism in positions of the looper above and below the clothplate of the sewing machine.

Referring to the drawings, the sewing machine is illustrated with the bed-plate 1 supporting the overhanging arm 2 terminating in the head 3. Journaled in bearings formed in the bed-plate is the main or driving shaft 4c, carrying the belt-wheel 5 and connected in the usual manner with the needle actuating rock-shaft 6, journaled in the overhanging arm. Secured to the rockshaft 6 is the crank-arm 7 connected by means of the link 8 with the needle-bar 9,

mounted for vertical reciprocation in the head 3 and carrying the needle 10.

Cooperating with the needle 10 above and below the cloth-plate W is the looper 11, carried by the looper-shaft 12 supported for -rocking movement upon the inclined bearing sleeve 13 projecting laterally from the rocking arm 14C. The rocking arm 14: 1s adapted to impart translatory movements to the looper and is provided with a boss 15, parallel with the inclined bearing sleeve 13 and journaled upon the rigid shaft 16 supported at its opposite ends in spaced bearings formed in the bracket 17, secured by means of a screw 18 to the bed-plate of the machine. Secured to the rocking arm 14 by means of the pivotscrew 19 and nut 2O is an apertured end of a link 21 of which the otherapertured end is secured in like manner by means of the pivot-screw 22 and nut 23 to a crank-arm 24 provided with a boss 25 secured upon a transverse rockshaft 26 by means of the set-screw 27. The rock-shaft is journaled in spaced bearings 23 and 29 formed in the bed-plate and is provided with a cranlnarm 30 having balland-socket connection with the pitman 31 actuated from a crank 32 on the main-shaft of the machine.

The looper derives from the crank-arm 24k its rocking movements to carry it above Y and below the cloth-plate through the intermedia-ry of a linkage that obviates the cam action heretofore employed to attain the desired cooperation between the needle and the looper. A slide block such as employed in the machine of the patent heretofore referred to not only requires eXtreme care in its manufacture, but is subject to wear under operation at high speed to such an ex tent as to cause after continued use looseness of the parts and a consequent loss in accurate timing of the looper, resulting in the skipping of stitches. rEhe linkage construction of the present improvement is readily manufactured and provides greater durability under conditions of operation at higher speeds than heretofore possible, attaining nevertheless the same efficient cooperation of the needle and the looper.

In accordance with the present construction, a crank-arm 33 is secured by means of a set-screw 34: to the looper-shaft 12 and is pivotally connected by a screw 35 to one end of a link 36, pivotally secured to the rocking arm 37 by means of a screw 38. The rocking arm 37 has a stationary ful- Crum parallel with andin advance of that of the rocking arm 14 and is provided with a boss 39 journaled upon the rigid shaft 40 supported at its opposite ends in spaced bearings formed in the. bracket 17. The rocking arm 37 is connected 'by means of a link 41 with the actuating crank-arm 24, and maintains throughout its movements a substantially parallel relation with the rocking arm 14. The mode of operation of the actuating elements for the looper is readily apparent from an inspection of Figs. 3 and 4 of kthe drawings and further reference thereto'is deemed unnecessary.

.Having thus set forth the nature of the invention, Vwhat I claim herein is 1. VIn an overseaming sewing machine, in combination, stitch-forming mechanism including a reciprocating needle, a looper cooperating with said needle upon opposite sides of the work, a looper carrying shaft, looper-shaft supporting` means, means for actuating said looper-shaft supporting means forY imparting translatory movements to said looper, a crank-arm upon said shaft, a. rocking-arm independent of said loopershaftfsupporting means, means for vactuating said rocking-arm, and a link connecting said'rocking-arm with said crank-arm.

2.In an overseaming sewing machine, in combination, stitch-forming mechanism including a reciprocating needle, a looper cooperating with said needle upon opposite sides of the work, two rocking arms, means for supporting said rocking arms independently of each other, means for supporting said looper for translatory movement upon one of said rocking arms, a link connecting said looper with the other of said rocking arms, an actuating element, and a link connection between each of said rocking arms and said actuating element.

3. In an overseaming sewing machine, in combination, stitch-forming mechanism including a reciprocating needle, a looper cooperating with said needle upon opposite sides of the work, a looper carrying shaft provided with a crank-arm, a rocking arm supporting said looper carrying shaft and adapted to impart translatory movements thereto, an actuating shaft, a crank-arm upon said shaft, a link connection between said crank-arm and said rocking arm for actuating the latter, a second rocking arm, means for actuating said second rocking arm and a link connecting said second rocking arm with said looper sha-ft crank-arm.

In testimony whereof, I have signed my name to this specification.

ALBERT I-I. DE VOE. 

